{	Problem: http://codeforces.ru/problemset/problem/57/B
	Verdict: Accepted
}
{$R+,S+,Q+,I+,C+,M+,O-}
uses SysUtils;
var i,n,k,j,m,t:longint; r:int64; b:array[1..100010] of longint; a:Array[1..100010,1..3] of longint;
procedure qsort_b(l,r:longint);
var i,j,x,y:longint;
begin
i:=l;
j:=r;
x:=b[(l+r) div 2];
repeat
  while b[i]<x do inc(i);
  while b[j]>x do dec(j);
  if i<=j then begin
    y:=b[i];
    b[i]:=b[j];
    b[j]:=y;
    inc(i);
    dec(j);
  end;
until i>j;
if l<j then qsort_b(l,j);
if i<r then qsort_b(i,r);
end;
begin
read(n,m,k);
for i:=1 to m do read(a[i][1],a[i][2],a[i][3]);
for i:=1 to k do read(b[i]);
r:=0;
qsort_b(1,k);
for i:=1 to m do begin
  for j:=1 to k do begin
    if (b[j]>=a[i][1]) and (b[j]<=a[i][2]) then begin
      t:=b[j]-a[i][1];
      inc(r,a[i][3]+t);
    end;
    if b[j]>a[i][2] then break;
  end;
end;
write(r);
end.